1. Field of the Invention
The present invention relates generally to a heat dissipation structure for LED lighting, and more particularly to a heat dissipation structure for LED lighting, which has better heat dissipation effect and is able to reduce noise.
2. Description of the Related Art
Recently, various green products meeting the requirements of energy saving and carbon reduction have been more and more respected. Following the rapid advance of manufacturing technique of light-emitting diode (hereinafter abbreviated as LED), various LED products have been widely applied in various fields as illumination devices, such as LED car lights, LED streetlights, LED desk lamps and LED lightings.
When high-power LED emits light, LED also generates high heat. The heat must be efficiently dissipated. Otherwise, the heat will locally accumulate where the light-emitting component is positioned to cause rise of temperature. This will affect the normal operation of some components of the product or even the entire product and shorten the lifetime of the product.
Taking a conventional LED lighting as an example for illustration, the conventional LED lighting lacks any heat dissipation structure for dissipating the heat. Therefore, after a long period of use, the heat generated by the LED will accumulate in the LED lighting without being effectively dissipated. This will lead to burnout of the LED due to overheating. To solve this problem, some manufacturers have developed various heat dissipation structures with for LED lightings.
Please refer to FIGS. 1a, 1b and 1c. FIG. 1a is a perspective exploded view of a conventional heat dissipation structure for LED lighting. FIG. 1b is a perspective assembled view of the conventional heat dissipation structure for LED lighting. FIG. 1c is a perspective view of a part of the conventional heat dissipation structure for LED lighting, seen from another angle. The conventional heat dissipation structure for LED lighting includes a light seat 10, a cap body 11 and a lens 12. A drive circuit 101 is disposed in the light seat 10. The cap body 11 has an open end 111 and is capped on the light seat 10. The cap body 11 has an internal support section 112. Multiple air inlets 113 are formed on the support section 112 between the cap body 11 and the support section 112. Multiple radiating fins 114 are formed on one side of the support section 112, which side is proximal to the light seat 10. A fan 115 is disposed on the side of the support section 112. The rear ends of the radiating fins 114 are annularly connected with each other. The center of the support section 112 is formed with an air outlet 116. The air outlet 116 extends from the other side of the support section 112 in a direction away from the radiating fins 114. An LED module 13 is fitted on the air outlet 116. One side of the LED module 13 is attached to the support section 112. The lens 12 is assembled on the cap body 11. The lens 12 is formed with a central hole 121 in alignment with the air outlet 116. The lens 12 is assembled and connected with the LED module 13.
Please now refer to FIG. 1d, which is a sectional view showing the operation of the conventional heat dissipation structure for LED lighting. When the LED module 13 emits light and generates high heat, the support section 112 and the radiating fins 114 will absorb the heat. In the meantime, the fan 115 operates to suck the ambient airflow of the LED lighting into the cap body 11. The fan 115 will forcedly drive the airflow toward the radiating fins 114. When the airflow reaches the radiating fins 114, the airflow will carry away the heat from the radiating fins 114. The hot wind is guided from the radiating fins 114 to the central air outlet 116 and sent out to dissipate the heat of the LED module 13.
According to the above, the conventional heat dissipation structure for LED lighting is able to dissipate the heat generated by the LED module 13. However, the heat dissipation effect is poor. This is because when the fan 115 drives the airflow to the radiating fins 114, the support section 112 will stop the airflow to affect the heat dissipation efficiency. As a result, the heat generated by the LED module 13 can be hardly effectively dissipated and the LED module 13 is likely to overheat. In some slight cases, the illumination of the LED lighting will be deteriorated and the lifetime of the LED lighting will be shortened. In some serious cases, the LED module 13 may damage (burn out). Moreover, the airflow is stopped, the LED lighting will make a noise. Furthermore, the air outlet 115 is not provided with any design for preventing alien articles from entering the light seat 10. As a result, alien articles may directly enter the light seat 10 from the air outlet 116 to affect the operation of the fan 115.
According to the above, the conventional heat dissipation structure for LED lighting has the following shortcomings:    1. The heat dissipation effect is poor.    2. The noise is increased.    3. The illumination of the LED lighting is likely to be deteriorated and the lifetime of the LED lighting is shortened.    4. Alien articles are likely to enter the light seat from the air outlet to affect the operation of the fan.